Pinking device for sewing machines



Sept. 18, 1934. v. J. SIGODA PINKING DEVICE FOR SEWING MACHINES 2 Sheets-Sheet l Filed-May 15, 1933 T O R jZyMa TORNEY- Patented Sept. 18, 1934 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to sewing machines, more particularly to pinking devices for such machines, and has for its object and purpose the provision of an improved construction of this character which will be economical in manufacture, while possessing the advantages of being highly efficient in use and providing for compactness.

An object of the invention is to provide a pinking device having a rotary horizontally disposed trimming mechanism furnished with cutting teeth for pinking the work being sewed by the sewing machine, and a roller by means of which to exert pressure against the teeth and upon the work which is being fed during the sewing operation. The invention also involves the provision of simple and practical means for supporting the roller so that it may be rotated by reason of the pressure which it exerts, to-

gether with means whereby at will to regulate the pressure of the roller for operating effectively upon different thicknesses and layers of work pieces. By the means for regulating pressure, the roller can be moved entirely clear of the work so that there will be no trimming of the work in connection with the operation of the machine.

Another object of the invention is the provision of a pinking device of the above character, constructed and mounted to receive its power from the four-motion feed of the sewing machine, so that the work can be'trimmed in connection with its advancement by the feed mechanism and while being stitched by the usual stitching mechanism of the machine.

The device of my invention may be usefully employed, for example, as an attachment for well-known types or makes of sewing machines having a four-motion feed, such as the Singer sewing machines, the Wilcox & Gibbs sewing machines and others. The device may also be embodied in these machines as a permanent feature thereof.

The nature of the invention, its general principles and objects above referred to, as well as other objects and advantages, and the manner in which the new and novel features of construction and operation may be embodied in practical form and means for the performance of the functions and the accomplishment of the results herein contemplated, will be hereinafter more fully described, with reference to the examples illustrated in the accompanying drawings, in which:

Figure 1 represents an end elevation of a portion of a sewing machine, showing applied thereto a pinking device made in accordance with my invention;

Fig. 2 is a top plan view, taken on the line 2-2 of Fig. 1;

Fig. 3 is an elevational view of the device detached and on a larger scale, parts being shown in section and parts being broken away;

Fig. 4 is a vertical sectional view taken on the line 44 of Fig. 3 and including a vertical section through the pinking wheel, throat-plate and feed dog;

Fig. 5 is a plan view of the feed dog;

Fig. 6 is a plan view, showing a fragment of fabric having a portion thereof cut away adjacent the line of stitching;

Fig. 7 is a top plan view showing another form of my pinking device;

Fig. 8 is a side elevational view thereof partially in section; Y

Figs. 9 and 10 are detail views of the stud supporting bracket for the roller; and

Fig. 11 presents top and side views showing a modified form of the feed dog.

Referring now to the accompanying drawings, and first to the form of construction shown in Figs. 1 to 5, inclusive, 15 denotes the end face plate forming part of the housing for the sewing mechanism of the machine; 16 denotes the needle bar; 17 the sewing needle; 18 the throat plate; 19 the feed dog and 20 the feed dog bar.

The feed dog or feeding mechanism 19 is operated with the well-known four-motion action for giving the work the usual intermittent straightaway feed, and it operates for this purpose in an opening 21 provided in the throat plate, in which is also provided the usual opening 22 for the reciprocation of the sewing needle through the work to stitch the same in the usual way during the time the feed dog is not feeding forward. The throat plate 18, as shown in Figs. 2 and 4, is made of a size to contain adjacent the opening 21 for the feeding mechanism and the opening 22 for the stitching mechanism, a rotary horizontally disposed bottom trimming or pinking mechanism 23. In the present embodiment, this trimming mechanism 23 rotates in an annular recess 24 provided in the throat plate and upon ball bearing devices 25 suitably interposed in a circular series between the bottom of the recess and the trimming mechanism. The recess 24 surrounds a boss 26 and the trimming mechanism has a central aperture 27 in which the boss is received ,sothat the trimming mechanism may rotate around the boss as a center. For holding the trimming mechanism operatively in place, I may provide a cap screw 28 the stem 28' of which is screw-threaded centrally within the boss.

The trimming mechanism is provided on its ,underface adjacent its periphery with a circular series of teeth 29 which are exposed in an opening 30 in the throat plate as the mechanism revolves. Said opening 30 is located closely adjacent the opening 21 for the feeding mechanism. The feed dog 19 is provided with an extension 31 having an up-turned portion provided with top teeth 32 adapted to engage with the teeth 29 whereby upon each forward feeding stroke of the feed dog the trimming mechanism will be given a rotative movement. With this arrangement the trimming mechanism is operated intermittently in conjunction with the forward feeding action of the feed dog and in a direction to aid in feeding the work. The upper face of the trimming mechanism adjacent the periphery thereof is provided with a circular series of cutting teeth 33 the design of which corresponds with the design of the trim to be produced on the stitched edges of the work. The cutting edges of the circular series of teeth 33 are substantially flush with the top surfaces of the throat plate and cap screw.

For cooperation with the cutting teeth of the rotary trimming mechanism or cutter, I provide a pressing mechanism which, in Figs. 1 to 4, inclusive, is constructed and arranged for support by the face plate 15. This pressing mechanism comprises a downwardly and rearwardly inclined bracket 34 having an integral horizontal portion 34' which is secured transversely to the lower end of the face plate by means of screws 35 which are passed through elongated slots 36 in the horizontal portion and threaded in the face plate. The elongated slots 36 make provision for relatively adjusting the position of the bracket. The bracket 34 carries a vertically movable arm 3'7, one end of which is pivoted at 38 to the lower portion of the bracket, while the opposite or free .end thereof carries a pressing roller 39 which may be constructed with ball bearing devices 40 interposed between its inner periphery and its axle 41 in order to provide for easy rotation of v the roller. Manually operated means are provided for adjusting the arm 37 vertically, and this means is represented as comprising a substantially circular member 42 provided with an upwardly projecting handle 43 and which turns on a stud axis-44 which projects laterally and centrally from a circular ratchet-like locking member 45, said stud axis having a threaded extension 46 which is screwthreaded in the bracket 34 so that the ratchetlike locking member 45 will be stationary while the member 42 is maintained between the bracket 34 and the member 45 for turning movement upon the stud axis 44. Said member 42 is provided adjacent its lower periphery and opposite the handle with an elongated cam-like eccentric slot 47 in which is received a pin 48 rigidly connected to the arm 37. This arrangement is such that when-the handle 43 is moved rearwardly or in a direction away from the lower portion of the face plate, the arm 37 will be moved downwardly; and conversely, when the arm is moved forwardly or toward the lower portion of the face the arm 37 will be moved upwardly.

The handle 43 contains a longitudinally movable plunger 49 provided at its lower end with a tooth 49' adapted to cooperate with ratchet teeth 50 provided on the periphery of the staionary locking member 45. Imprisoned within the handle is a coil spring 51 which normally urges the plunger downwardly to engage the tooth 49 with the ratchet teeth. In the present embodiment, the ratchet teeth 50 are so inclined that the tooth 49 will slide thereover upon moving the handle ina rearward direction whereby to force the arm 37 downwardly; and a finger piece 52 attached to the plunger and projecting through an elongated slot 53 of the handle provides means whereby the plunger may be lifted for withdrawing the tooth thereof from the ratchet teeth when it is desired to elevate the arm 37. This construction makes it possible for manually elevating and lowering the arm 37 and consequently the pressing roller 39, and also for locking the arm 37 in that position in which it is desired to maintain the pressing roller.

The pressing mechanism is so arranged that the roller 39 may be moved upwardly to entirely clear the work which is being moved by the feeding mechanism and stitched by the stitching mechanism. This provision makes it possible to use the sewing machine in the usual way without pinking the stitched edges of the work. On the other hand, when it is desired to pink the stitched edges of the work, the pressing mechanism is operated so that the pressing wheel 39 will press the work being fed and stitched into the cutting teeth 33 so as to trim off the stitched edges of the work by a line of pinking as 54 adjacent the stitched line 55. It will be appreciated that the work which is being fed by the feed dog and stitched by the sewing needle will move rearwardly across a segment of the rotary cutter and upon the cutting teeth thereof so that the pressing roller can be brought into play to cause a frictional pressure upon the work and against the cutting teeth below the work, with the result that the work adjacent the stitched line 55 will be instantly trimmed in accordance with the design of the cutting teeth at the forward straightaway feeding periods of the work. In this connection, it will also be appreciated that the roller in exerting frictional pressure upon the cutting teeth serves as means whereby to aid in the feeding of the work during the cutting thereof.

The roller should be positioned so as to press I the work upon the cutting teeth on a point of contact in a line as 56 spaced somewhat beyond or to therear of the center line 57 of the rotary cutter. By this expedient, the work will not so easily be drawn from its straightaway course by the drag of the rotary cutter. A vertical guide plate 58 may extend acrossthe segment of the rotary cutter to define the straightaway course of the work, and such guide plate through contact therewith of the work being fed, will overcome the rotary drag of the cutter and keep the work on its straightaway course. The guide plate 58 may project rearwardly from a base member 59 secured by a screw 60 upon the throat plate, and said base member 59 mayhave an elongated slot 60' for the stem of the screw in order to conveniently provide for the adjustment of the guide plate as may be necessary for defining the course of travel of the work across the segment of the rotary cutter.

In Figs. 7 to 10, inclusive, I disclose another form .of construction for my pinking device, in which the throat Plate 61 is elongated so as to serve as the supporting means for the pinking device. In this form of construction, the feed dog 62 has an extension 63 provided with teeth 64 which engage a circular series of teeth 65 provided on a rotary cutter 66 which turns in a recess 6'7 about a center boss 68. In this instance, the cap screw for holding the rotary cutter operatively in place and whose stem is threaded into the boss 68, is provided with a dome-like head 69 for the purpose of keeping the work from being drawn from its straightaway course by the drag of the rotary cutter.

The means for supporting the pressing roller- '70 comprises a curved arm '71 the end '72 of which is mounted upon and between trunnionlike screws 73 which are screw-threaded for adjustment in lugs '74 upstanding from the outer or remote and of the throat plate. Adjacent its pivoted end, the arm '71 is formed with, a hollow vertically extending boss '75. Extending upwardly through the hollow interior of this boss is a pin '76 the lower end of which is secured rigidly in the throat plate. An expansion spring 7'7, coiled around the pin '76 is imprisoned between the top surface of the throat plate and the lower end of the boss '75 so as to constantly urge the arm '71 into an elevated position in which the pressing roller '70 will be clear of the work being fed and sewed on the machine. For moving the arm '71 downwardly against the urge of the spring '77 in order to contact the pressing roller '70 with the work, I provide a handle '78 formed with a circular portion '78 which is screw-threaded upon the upper portion of the pin 76 adjacent the top end of the boss '75. By turning this handle in one direction, the arm '71 will be forced downwardly compressing the spring 77, and by reason of the threaded engagement between the circular portion '78 and the pin '76 the arm will be maintained in that precise position to which it has been moved by the manipulation of the handle '78.

In this embodiment, the forward end '79 of the arm is made with corresponding furcations '79 between which is adiustably engaged an elongated ear 80 formed integrally with a cross head 81 in which is screw-threaded the inner end of a pin 82 which serves as the axis for the pressing roller '70. The ear 80 is provided with an elongated slot 83 for receiving the screw bolts 84 which pass transversely through the furcations '79 and have screw-threaded engagement in one of these furcations. This arrangement provides for the adjustment of the head 81 relatively upon the arm 71. In order that the pressing roller '70 will rotate easily and freely, I provide between its inner periphery and the circumference of the pin 82, a suitable roller bearing device 85; and in addition to this I may provide between the head 81 and the adjacent end of the pressing roller a suitable ball bearing thrust collar 86. The pin 82 may be secured rigidly in the head 81 by means of a pinch screw 8'7 or equivalent device.

In Fig. 11, I show a modified form of the feed dog in which a latch finger 88 is pivoted at one end at 89 to the extension 90 of the feed dog. This latch finger is provided with upwardly projecting teeth 91 for engagement with the teeth on the underside of the rotary cutter and a spring 92 normally urges the latch finger into the position in which the teeth 91 thereof will be engaged with the teeth of the rotary cutter -when the feed dog makes its forward feeding stroke.

In each of the forms of construction, the ratary cutter cooperates with the feed mechanism, being operated by the latter to trim the stitched edges with each forward movement of the work. Movement of the rotary cutter is intermittent, as it is moved with the forward feeding stroke of the feed dog and remains idle during the time the feed mechanism isnot feeding forward, during which period the needle is passing through the work to stitch the same.

It will be recognized that in each of the forms of construction, the pressing roller may, at will, be elevated and lowered so as to obtain, irrespective of the thickness or thinness of the work or of the number of layers to be trimmed, the degree of pressure necessary to effect a sharp and clean trim of the stitched edges. The cutting teeth of the rotary cutters may be fashioned to produce any design or character of ornamental trim desired, and it will be understood that in each of the forms of construction, by removing the cap screw from the rotary cutter, the latter can be readily removed and a new cutter applied in its place.

Another advantage in each of the forms of construction is to be found in the fact that the supporting structure for the pressing roller may be adjusted laterally, that is, in the direction of the straightaway feed of the work so that the point at which the roller makes contact with the cutting teeth can be varied with respect to the center line of the rotary cutter. In the form of construction shown in Figs. 1 to 4, this is accomplished by loosening the screws 35 and adjusting the position of the bracket arm 34'. In the form of construction shown in Figs. '7 to 10, this adjustment can be made by loosening the screws '73, the space between the lugs '74 providing for lateral adjustment between them of the arm end '72.

As many changes could be made in the above constructions and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Moreover, the terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but realize that various modifications are proper within the scope of the invention claimed.

I claim:-

1. In a sewing machine having feeding mechanism including a feed dog, a rotary horizontally disposed member engaged with the dog for rotation thereby and operative as a bottom cutter adapted to trim the work, a pivoted arm, a roller on said arm for frictionally pressing the work upon the cutter, and means for moving said arm for regulating the pressure of the roller onthe work, said means including an operating member with an eccentric device connected with the arm, and means for'locking the operating member in a position of adjustment.

2. A pinking attachment for sewing machines, operable by the feed dog of the machine and consisting of a bottom horizontally disposed rotary member having on its top a circular series of cutting teeth adapted to trim the work with a predetermined design, and pressure means acting downwardly against the cutting teeth for trimming the work fed between these parts by the feed dog, and having a relatively wide range of movement, said pressure means and cutting teeth being effective to aid in the feeding of the work which is trimmed thereby, manually operated means for adjusting the position of the pressure means, and self -setting retaining means tending normally to retain the pressure means in its adjusted position.

3. In a sewing machine having feeding mechanism including a feed dog, a rotary horizontally disposed member engaged with the dog for rotation thereby and having top cutting teeth adapted to trim work fed by the feeding mechanism, a curved arm movable on a pivot and having a head at its free end overhanging said cutter, a roller carried by said head for frictionally pressing the work upon the cutting teeth to effect the cutting operation and mounted by anti-friction means for free turning by reason of exerted frictional pressure, manually operated means for moving said arm for regulating the pressure upon the work, and self-setting retaining means for firmly holding the arm in that position to which it is moved by the manually operated means.

4. In combination with a sewing machine, its stitching needle, throat plate and feed mechanism, of a member disposed for rotation in the throat plate and having top cutting teeth adapted to trim work fed by the feed mechanism and sewed by the stitching needle, a transmission connection between the feed mechanism and said member whereby to rotate the latter from the operation of the former, a guide for directing the work which is fed by the feed mechanism across a segment of said member and over the cutting teeth thereof, roller pressure means having a relatively wide range of movement in a plane parallel with the plane of the guide and adapted to engage the directed work and press the same upon the cutting teeth to effect the trimming operation, and self-locking holding means tending normally to hold the roller pressure means in any one of various positions within its range of movement.

5. In a sewing machine, the combination with a throat plate and feed dog, of a member disposed for rotation in the throat plate and having top cutting teeth adapted to trim work fed by the feed dog, cooperating teeth between the feed dog and member whereby to rotate the latter by the operation of the former, roller pressure means having a relatively wide range of movement and adapted to engage the feeding work and press the same upon the cutting teeth to effect the trimming operation thereby, and self-locking holding means tending normally to hold the roller pressure means in the position to which it is moved.

6. A sewing machine having, in combination, a support for stitching mechanism, a throat plate and feed mechanism, a bracket on the support provided adjacent the stitching mechanism with a vertically movable arm having movement toward and away from the throat plate, operating means on the bracket including an eccent'ric connected with the arm for moving the arm, means for locking the eccentric in a position of adjustment, a roller carried by the arm, atrimming member rotatably disposed in the throat plate and having top cutting teeth for trimming work pressed thereon by the roller and moved by the feed mechanism, and means operated by the feed mechanism for rotatingsaid trimming member.

'7. A pinking attachment comprising, in combination with a throat plate and feed dog, an arm pivoted for vertical movement toward and away from the throat plate, means for manually moving said arm, self-setting means for the arm, tending normally to retain it in the position to which it is moved, a roller carried by said arm, and therewith movable, and also having free rotary movement, a trimming member rotatably disposed in the throat plate and having top cutting teeth for trimming work pressed thereon by the roller and moved by the feed dog, and a connection between the feed dog and trimming operation of the former.

VICTOR J. SIGODA. 

